蚓粪对盐胁迫下小麦幼苗生长及光合特性的影响

Effect of Vermicompost on Growth and Photosynthetic Characteristic of Wheat Seedling under Salt Stress

为明确添加蚓粪对盐胁迫下小麦幼苗生长及光合特性的影响机理,通过向基质中分别添加10%、20%、40%(苗死亡)比例的蚓粪,同时设不添加蚓粪的单盐胁迫处理和空白对照处理(CK),分析了添加蚓粪后盐胁迫(150 mmol·L^-1 NaCl)下小麦生长指标(叶长、叶宽、叶面积,地上和地下部干重、根冠比)、气体交换参数及光合色素含量的变化。结果表明,盐胁迫下小麦幼苗各生长指标与CK相比略有下降,但差异不显著。添加蚓粪后,小麦幼苗叶长、叶宽、叶面积、地上部分干重、总干重以及叶绿素a、叶绿素b、叶绿素总含量及类胡萝卜素含量较未添加蚓粪处理均呈明显的上升趋势,而根冠比则呈下降的趋势。添加蚓粪对盐胁迫下小麦叶片气体交换也产生了显著的影响。盐胁迫下,小麦叶片净光合速率显著低于CK,但添加蚓粪后,净光合速率呈明显的上升趋势。这说明基质中添加适量蚓粪可以有效促进小麦幼苗生长和光合作用。

In order to clarify the mechanism in the effects of vermicompost on the growth and photosynthetic characteristics of wheat seedlings under salt stress,the effects of vermicompost on growth,gas exchange and photosynthetic pigment of wheat under salt stress were studied by adding different proportion of vermicompost to substrate.There were four ratios of vermicompost:0,10%,20%and 40%(seedling death).Each treatment was added with 150 mmol·L^-1 NaCl solution to simulate salt stress,and the treatment without vermicompost and NaCl solution was used as control(CK).The results showed that the growth indices of the plants decreased slightly compared with those of CK under salt stress,but the difference was not significant.After adding vermicompost,the leaf length,leaf width,leaf area,above-ground part and total dry weight of wheat seedlings all increased obviously(P<0.05),but the ratio of root to shoot decreased.The contents of chlorophyll a,chlorophyll b,total chlorophyll and carotenoid were also increased by adding vermicompost.The net photosynthetic rate,stomatal conductance,transpiration rate and water use efficiency(WUE)of wheat under salt stress were significantly affected by vermicompost(P<0.05).The net photosynthetic rate of wheat under salt stress was significantly lower than that of the control,but the net photosynthetic rate increased obviously after adding vermicompost.The results indicated that the addition of vermicompost to the substrate can promote the growth and photosynthesis of wheat effectively.The results provide data support and theoretical basis for wheat planting in saline-alkali areas.